A method according to one embodiment includes communicating a wireless advertisement that identifies a clock status of a real-time clock of the access control device, wherein the clock status includes a clock status value indicating that the real-time clock has not been set, establishing a wireless communication connection with a computing device in response to the wireless advertisement, transmitting a session random value to the computing device, receiving a clock update token from the computing device, wherein the clock update token is indicative of an authority of the computing device to update the real-time clock of the access control device, authenticating the clock update token based on at least the session random value, and updating the real-time clock based on a received update time in response to successful authentication of the clock update token.